In a wide number of settings, it is important to be able to accurately calculate the volume of a liquid that is contained in a container, such as glasswear. Existing techniques are cumbersome and very time consuming and are prone to error. For example, one technique is simply manual observation of the liquid and then using some type of graduation system to calculate the volume of the liquid. Other techniques involve using a measurement device which measures the liquid after it has been transferred from the container to the measurement device; however, in settings where precision is required, this technique is not that effective since some of the liquid may evaporate or be left behind. All of these techniques are not particularly suited for use in an automated system where a number of containers, such as product containers, are prepared by adding a prescribed volume of liquid and subsequently further processed, such as packaging of the products.
One particular industry that uses a considerable number of product containers is the medical and pharmaceutical industries. As technology advances, more and more sophisticated, automated systems are being developed for preparing and delivering medications by integrating a number of different stations, with one or more specific tasks being performed at each station. For example, one type of exemplary automated system operates as a syringe filling apparatus that receives user inputted information, such as the type of medication, the volume of the medication and any mixing instructions, etc. The system then uses this inputted information to disperse the correct medication into the syringe up to the inputted volume. In some instances, the medication that is to be delivered to the patient includes more than one pharmaceutical substance. For example, the medication can be a mixture of several components, such as several pharmaceutical substances.
By automating the medication preparation process, increased production and efficiency are achieved. This results in reduced production costs and also permits the system to operate over any time period of a given day with only limited operator intervention for manual inspection to ensure proper operation is being achieved. Such a system finds particular utility in settings, such as large hospitals, including a large number of doses of medications that must be prepared daily. Traditionally, these doses have been prepared manually in what is an exacting but tedious responsibility for a highly skilled staff. In order to be valuable, automated systems must maintain the exacting standards set by medical regulatory organizations, while at the same time simplifying the overall process and reducing the time necessary for preparing the medications.
Because syringes are used often as the carrier means for transporting and delivering the medication to the patient, it is advantageous for these automated systems to be tailored to accept syringes. However, the previous methods of dispersing the medication from the vial and into the syringe were very time consuming and labor intensive. More specifically, medications and the like are typically stored in a vial that is sealed with a safety cap or the like. In conventional medication preparation, a trained person retrieves the correct vial from a storage cabinet or the like, confirms the contents and then removes the safety cap manually. This is typically done by simply popping the safety cap off with one's hands. Once the safety cap is removed, the trained person inspects the integrity of the membrane and cleans the membrane. An instrument, e.g., a needle, is then used to pierce the membrane and withdraw the medication contained in the vial. The withdrawn medication is then placed into a syringe to permit subsequent administration of the medication from the syringe.
If the medication needs to be reconstituted, the medication initially comes in a solid form and is contained in an injectable drug vial and then the proper amount of diluent is added and the vial is agitated to ensure that all of the solid goes into solution, thereby providing a medication having the desired concentration. The drug vial is typically stored in a drug cabinet or the like and is then delivered to other stations where it is processed to receive the diluent. As is known, the drug vial typically includes a pierceable septum that acts as a seal and prevents unwanted foreign matter from entering into the drug vial so as to contaminate the contents thereof as well as keeping the contents safely within the interior of the drug vial when the drug is stored or even during an application. The septum is typically formed of a rubber material that can be pierced by a sharp transfer device to permit communication with the interior of the drug vial and then when the transfer device is removed the small piercing hole seals itself due to the material properties of the septum.
Typically, the medication is aspirated or otherwise withdrawn from the drug vial into a fluid conduit that can be in the form of a section of tubing or can be a cannula or a syringe. Unfortunately and as previously indicated, one of the difficulties in the filling process involves checking to see if the delivered volume of fluid is the correct amount since there are a number of reasons, such as the presence of foreign matter and mechanical malfunction, as to why the delivered volume of fluid can either be too great or too little compared to the intended delivery amount. When dealing with preparing medications, as well as other applications that involve a great degree of precision, it is important that the integrity of the fill not be jeopardized and as a result, it is a very time consuming and arduous task to confirm that the syringe or other type of container contains the correct amount of fluid.
What is needed in the art and has heretofore not been available is a system and method for automating the medication preparation process and more specifically, a safety and cost reducing feature that is capable of determining a characteristic of the syringe fill and more particularly, is capable of determining and checking the integrity of the syringe fill.